To this end, proposals have been made in the prior art to provide screen wiping apparatus for openable windows of vehicles, in which the wiper blade (and therefore the wiper) is positioned off the window when the wiping system is out of use. In these cases the wiper is retracted away from the window once opening of the window is detected during operation of the wiper motor.
However, when the wiper passes off the window and on to the bodywork of the vehicle, the rubber wiping strip of the wiper blade rubs on the paintwork of the vehicle and this gives rise to the danger of scratching of the paintwork if any dirt is stuck to the wiping strip. In addition, the rubber wiping strip itself is in danger of being damaged by these repeated movements from the window on to the bodywork and vice versa.
One solution to this problem consists, in the manner which is described in particular in U.S. Pat. No. 4,310,943, in guiding the screen wiper arm in a ramp or a guide finger when it is desired to retract the screen wiper off the window. Although this ramp or guide finger does enable direct contact between the rubber wiping strip and the bodywork of the vehicle to be avoided, this solution has a major disadvantage, in that when the wiper blade meets the ramp, the resulting impact makes a noise which is highly disagreeable for the occupants of the vehicle. In addition, there is a danger of people, and particularly children, getting their fingers trapped between the wiper blade and the ramp.